Feb., 1922] 
ARNDT THE GROWTH OF FIELD CORN 
57 
III. The Effect of Aluminum Salts and Acids Upon Growth in Solution "A" 
The object of this series of experiments was to determine the relative 
toxicity of hydrochloric, nitric, and sulphuric acids and their corresponding 
aluminum salts. The solution was modified by the addition of the acids 
and the salts as shown in table 3. As previously stated, the aluminum 
salts were precipitated in this solution, and the concentration added does 
not represent the amount remaining in solution. The results, consequently, 
do not represent the real relation between the toxicity of the acid and that of 
the salts. The plants were grown for 30 days during the month of April in 
a shaded greenhouse. Pint Mason jars containing 400 cc. of the culture solu- 
tions were used. The results are shown graphically in figure 3. The 
weather was very favorable during the first portion of the period. There 
was practically no sunshine during the last week. This fact, undoubtedly, 
accounts for the small change in the pH value for the last week of growth. 
Table 4. The Efect of Acids and Iron and Aluminum Salts upon Growth in Solution "il " 
v50l. ri 
plus 
i\or- 
rnality 
Yield c 
Ser. I 
)f Tops 
2 
Yield of . 
Roots 
2 
Transpir- 
ation 
2 
Ini- 
tial 
pH 
Af 
Gro 
I 
ter 
wth 
2 
Control 
100% 
100% 
100% 
100% 
4.9 
4-9 
6.2 
H2SO4 
(17.5 gm.) 
(20.2 gm.) 
(0.58 gm.) 
(745 CC.) 
0.0002 
97 
3.7 
4.6 
.0004 
71 
78 
71 
74 
3-5 
4-3 
6.2 
HNO3 
.0006 
88 
. 67 
65 
69 
3-2 
3.5 
6 
.0002 
90 
3-7 
4.6 
.0004 
82 
76 
69 
68 
3-4 
4-3 
.0006 
68 
62 
55 
51 
3-2 
4-5 
5-6 
HCl 
.0002 
97 
3-7 
4-3 
.0004 
82 
88 
71 
84 
3-5 
3-7 
6.2 
<( 
FeS04 
.0006 
69 
63 
53 
49 
3-2 
3-4 
5-4 
.0002 
72 
71 
66 
60 
4.6 
4.8 
4.4 
.0004 
62 
52 
54 
50 
4.6 
4.6 
3-8 
Fe2(S04)3 
.0006 
41 
4.2 
4-3 
.0002 
100 
5 
.0004 
72 
67 
66 
52 
0-7 
4-3 
4-7 
Fe(N03)3 
.0006 
75 
73 
61 
67 
3.5 
3.5 
4-7 
.0002 
V 
4 
4-3 
.0004 
69 
62 
65 
54 
3-7 
4-3 
4.6 
FeCl3 
.0006 
52 
64 
57 
59 
3-5 
4-3 
4-7 
.0002 
95 
4 
4.2 
.0004 
86 
63 
61 
56 
3.6 
4-3 
4-7 
Al2(S04)3 
.0006 
67 
51 
51 
54 
3.5 
3-5 
3-3 
.0001 
91 
88 
88 
84 
4.2 
4.8 
5.8 
.0002 
84 
74 
73 
66 
4.1 
4-7 
4.8 
.0004 
73 
62 
59 
52 
3-9 
4.2 
4.2 
A1(N03)3 
.0006 
64 
57 
67 
53 
3.8 
3-9 
4 
.0002 
63 
66 
67 
63 
4.2 
4-7 
4.6 
.0004 
53 
57 
50 
52 
4.2 
4-3 
3-7 
.0006 
50 
53 
48 
45 
4 
4.1 
4.2 
A1C13 
.0002 
73 
74 
66 
4.2 
4 
.0004 
64 
62 
52 
4.1 
3-9 
.0006 
64 
60 
49 
3-9 
3-5 
